Traffic Influence Degree of Urban Traffic Accident Based on Speed Ratio

The analysis of traffic influence degree of urban traffic accident has a significant and real-world importance for estimating traffic emergency grades and adopting corresponding countermeasures. In this paper, analogized with water wave ripple theory, the ratio of speed before-to after-accident was proposed as the traffic impact coefficient to evaluate the traffic influence of an accident. In this paper, we limited the study to a certain type of traffic accident and established a standard theoretical model of the traffic impact coefficient. Thirty-five traffic accidents were sorted by using MATLAB, and the variable control method based on data filtering was adopted. According to the variations of different traffic accident characteristics and considering the differences in remaining road capacity after the accident, the modified factor of each accident was obtained by calculating the lane utilization factor of urban roads. The traffic influence degree value was calculated via double integral, which was used to evaluate the comprehensive traffic impact of the accident on the surrounding road network. Finally, the comprehensive traffic influence value was calculated by using the established standard model and the model built according to simulation data on the basis of a VISSIM simulation of an assumed accident. Results show that the comprehensive traffic influence values of the two methods were 0.666 and 0.648. The error of the two values was 3.8%, which shows the feasibility of the established evaluation model for traffic impact of accidents. The result shows that the proposed model proposed in this paper can be used by traffic management departments to quickly respond to accidents.